besides the idea of -iDaze
this is for people who arent the greatest at getting high kill streaks and still want them, if you are one of them assault is not for you

Using the support class can get you a lot of points in many ways, i would recommend using ballistic vest(5 kills/Points)-Get points when teammates pick one up each time
recon drone(10 kills/Points)- 100 points every time you tag an enemy
stealth bomber(12 kills/Points)- to get more kills unlike these other killstreaks
even if you die you still keep your progress towardss these killstreaks and all of these are obtainable multiple times in a match
Now -iDaze said that putting hardline on and using specialist is a fast way, i used this and i get more points by doing this than i did with his way